Mask structures are commonly used to control the etching of silicon trenches and for the control of the implantation of impurities into such structures. Such mask structures are complex and frequently cannot be used in connection with certain substrate materials, for example, silicon carbide (SiC) which requires long and high temperature process steps. It would be desirable to have a mask process that can be used with SiC substrates, including 4H silicon carbide, as well as other substrates such as silicon and the like, in which a single mask structure can be employed for the trench etch process or for both the trench etch and implantation process.